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What’s Up?

The stars are doing their job

By Vernon WhetstoneAmateur Astronomer

What we have all been waiting for is about to happen, spring is about to be sprung. Tomorrow in fact. On Thursday, March 20, at 10:57 a.m. MDT the Sun will cross the equator into the Northern Hemisphere bringing the spring season. Our friends in the southern hemisphere will start to enjoy a respite from the heat of summer when autumn begins for them. The event is called the vernal equinox. The word vernal referring to the idea of green and the word equinox alludes to equal day and night. If you are standing on the equator that would be true, on that day the hours of day and night would be an equal 12-hours each, however, not all of us are. For example, we here in southwest Nebraska are almost standing on the line marking 40 degrees north of the equator—almost half-way from the equator to the North Pole, so our equal day and night will be on Monday, March 17, when daylight is 11 hours and 59 minutes. The following day, Tuesday, March 18, daylight will be 12 hours and two minutes long. If you have been watching the constellations and using them for a sky clock, they are another clue that the seasons are changing. For example, looking west at sunset we see our old friend Pegasus (a constellation of autumn) sinking below the horizon while in the east Leo, Cancer, and Coma Berenice, all constellations of spring—are rising. If we look due south the bright constellations of winter are standing almost right overhead, Orion, Taurus, and Gemini. Now, let’s go to sunrise to see what the constellations are telling us. Looking east at sunrise we find the Summer Triangle—Vega, Deneb, and Altair, rising and the constellations of summer, Scorpius and Sagittarius, standing in the south. So, in addition to our calendar, we can use the sky to give us clues as to what season is going, what season is, and what season is to be. It is no wonder that ancient farmers used the stars to help them keep track of the seasons and for planting and harvest. You see, the sky is not there just for our entertainment, it has a job to do. SKYWATCH: Third-quarter moon, Sunday, March 23. Thursday morning, March 20, at about 2 a.m. MDT, the moon will be above and right of the ringed planet Saturn. The next day at about the same time it will be much closer and to the moon’s lower left. The pair will almost be in the same binocular field of view. Saturday morning, March 22, brilliant Venus will be at its best. Look about an hour before local sunrise. Venus is as far as it gets from the Sun on this go-round. If you have a telescope you will be able to see that Venus looks like a half-moon, lit only on one side. Just for your information, if you would like to know where Pluto is, be outside on the morning of Monday, March 24, looking south for the moon. The most distant and smallest planet in the solar system—yes, I still consider Pluto as a planet—will be about five degrees to the lower left of the moon. You won’t be able to see it, even with a telescope, but at least you will know where it is in case someone asks you. NEXT WEEK: The eclipse is coming, the eclipse is coming, and more astronomical blathering.